- The diagnosis of MDS must be confirmed by a bone marrow aspirate and/or biopsy revealing refractory anemia, or primary refractory leukopenia or thrombocytopenia with morphologic features of MDS; patients with 5q- syndrome are ineligible; patients with RA and RARS are eligible provided they are transfusion dependent. Patients with chronic myelomonocytic leukemia (CMMoL) are eligible; allogeneic BMT will be the treatment priority for patients with HLA-matched siblings; MDS patients for whom intensive chemotherapy has failed to achieve remission will be candidates for this trial if the chemotherapy was administered > 1 month prior to enrollment, and performance status is adequate; patients are also eligible having previously progressed on other institutional trials, including phenylbutyrate and ATRA or 5'-azacytadine